/Engine/Source/Runtime/Slate/Public/Framework/MultiBox/MultiBoxBuilder.h
Adds a button to a row
void AddButton ( const [TSharedPtr](API\Runtime\Core\Templates\TSharedPtr)< const [FUICommandInfo](API\Runtime\Slate\Framework\Commands\FUICommandInfo) > InCommand, const [TAttribute](API\Runtime\Core\Misc\TAttribute)< [FText](API\Runtime\Core\Internationalization\FText) > & InLabelOverride, const [TAttribute](API\Runtime\Core\Misc\TAttribute)< [FText](API\Runtime\Core\Internationalization\FText) > & InToolTipOverride, const [FSlateIcon](API\Runtime\SlateCore\Textures\FSlateIcon) & InIconOverride )